Gyrotron based on a superconducting magnet

  • S. N. Spark
  • A. W. Cross
  • A. D. R. Phelps


The replacement of conventional pulsed magnetic field coils previously used to generate the intra-cavity B-field with an 11T superconducting magnet is reported. The resulting more stable mm-wave output pulse is shown and the refurbishment requirements of both the field emission, field-immersed, cold cathode and Marx bank spark gaps demonstrated. This system proved to be tunable, oscillating from 20GHz up to 110GHz, with peak power levels of 450kW and 300kW respectively. Other operating parameters were also examined including mm-wave pulse length as a function of anode-cathode position. The pulse length increased from 87±6ns to 310±10ns with a 2.5 cm horizontal transit of the cathode away from the anode. A similar effect was witnessed with the increase of the intra-cavity B-field from 1.00T to 5.00T resulting in the mm-wave pulse duration increasing from 250±40ns. Second harmonic operation of the cavity resulted in ∼0.5kW of radiation observed at 96GHz. The pulse-to-pulse mm-wave stability coupled with the mode selectivity of the ohmic-Q-dominated cavity resulted in the identification of several oscillating modes including the TE12, cut-off frequency 21.1 GHz, the TE02, cut-off frequency 29.1 GHz, the TE35 at ∼74 GHz and the TE14,2, at ∼88GHz.

Key words

Gyrotron tunable gyrotron superconducting magnet 


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Copyright information

© Plenum Publishing Corporation 1992

Authors and Affiliations

  • S. N. Spark
    • 1
  • A. W. Cross
    • 1
  • A. D. R. Phelps
    • 1
  1. 1.Department of Physics and Applied PhysicsUniversity of StrathclydeGlasgowScotland

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